K1500 AWD SWAP

[Nad_Yvalhosert]

The Auto mode locks the front axle, which is connected to the front drive shaft. When the PCM detects wheel slip, via the front wheel speed sensors, it activates the encoder motor on t-case switching from 2wd to 4x4. When there's no more slip, the t-case goes back to 2wd, but the front axle stays engaged

 

[alpinecrick]

Nad,
Why does the 246 need the blue fluid?

 

[b454rat]

Get a t-case from a 90s AWD Astro van. Pretty sure they are same as the typhoon/cyclone.

 

[John Carlsen]

the astro van BW transfer case up until the early 90's did have the viscous transfer case, I drove one for a few years and it did work a lot better than the later units trying to electronically switch the front axle into engagement after the wheel sensor report a slip. With the viscous coupling the front axle actuator was eliminated and the transfer case was always engaged.

GM's electric all wheel drive system were lacking at best.
The auto feature that was available was even worse.
Trying to control the transfer case clutch and the front axle actuator at every stop sign in the winter usually led to an early death on both units and they are all in the junkyard or crushed by now,

 

[gearheadE30]

As far as I know, every GMT400 Escalade and Yukon Denali came with that Autotrac transfer case. Plenty of those are still on the road.

I didn't realize it was just cycling the tcase when slip was detected though; that's a bummer vs a 'real' AWD mode.

 

[b454rat]

The autocrap in the GMT400 wasn't active all the time. If it was in auto mode, it was in 2wd till it sensed wheel slip. Then it would go into 4wd. I had one, I don't remember what was wrong with it, but I'd put it in 4wd, bout half hour later it would work. For a soccer mom, prolly worked as it was designed. But i'd rather have lock outs with a level, then you KNOW it would work. But for now my Yukon has the push button 4wd, just not the Autocrap.